]> 2026-07-31T07:28:13+00:00 WBR0256 0 en Bernard-Soulier syndrome While Bernard-Soulier syndrome (BSS) is a platelet disorder characterized by a defect in platelet adhesion to von Willebrand factor. BSS may result in a bleeding disorder and prolongation of bleeding time. However, patients usually have thrombocytopenia, which is not present in this patient. Hemophilia A Hemophilia A is an X-linked bleeding disorder characterized by internal bleeds as opposed to the cutaneous and mucosal bleeds observed in this patient. Labs in hemophilia reveal a marked elevation in aPTT and a normal bleeding time. Idiopathic thrombocytopenic purpura Idiopathic thrombocytopenic purpura (ITP) is an acquired bleeding disorder caused by decreased production and increased destruction of platelets due to formation of auto-antibodies against GpIIb/IIIa. ITP is associated with several environmental exposures, including hematological malignancies, HIV infection, HCV infection, and lupus erythematosus. The long history of bleeding and normal platelet counts make ITP a less likely diagnosis in this patient. Thrombotic thrombocytopenic purpura (TTP) Thrombotic thrombocytopenic purpura is a bleeding disorder that may be inherited (deficiency of ADAMTS13) or acquired (auto-antibodies against ADAMTS13). ADAMTS13 is a metalloprotease responsible for cleaving vWF into smaller subunits. Acquired TTP is common in pregnancy and the early post-partum period. In TTP, the circulating multimers of vWF increases platelet adhesion to areas where subendothelial collagen is exposed. TTP is characterized by pentad of manifestations: Microangiopathic hemolysis, thrombocytopenia, fever, neurological symptoms, and renal disease. The lack of other TTP signs and symptoms make the diagnosis of TTP unlikely in this patient. von Willebrand disease von Willebrand disease is an autosomal dominant bleeding disorder caused by dysfunctional platelet adhesion. Patients with von Willebrand disease may present similarly to the patient in the vignette. Typically, patients with VWD have a prolonged bleeding time, normal/prolonged aPTT, and normal PTT and platelet count. Genetics Pathophysiology A 14-year-old girl is brought to her pediatrician's office for excessive menstrual bleeding. The patient is distressed because her periods are very heavy, and she fears that she may stain her pants during school. She has a long history of easy bruisability and nosebleeds, and she reports that her gums often bleed excessively after brushing her teeth. The physician orders laboratory tests which reveal the following findings: prothrombin time (PT) = 13 seconds (normal: 11-15); activated partial thromboplastin time (aPTT) = 70 seconds (normal: 30-50 seconds); platelet count = 287 x 10⁹/L (normal: 150-400 x 10⁹/L); and bleeding time = 22 minutes (normal: 2-15 minutes). What is this patient's most likely diagnosis? E Hematology 2020-10-27T23:56:22Z 2459150.4974769 WBR0256